import random
f={}
a='abcdefghijklmnopqrstuvwxyz'
for i in range(100):   
    b=random.sample(a,2)
    i=''.join(b)
    if i in f.keys():
        f[i]+=1
    else:
        f[i]=1
l=sorted([(j[1],j[0]) for j in f.items()],reverse=True)
print(l)
        
# 完成的不错
